1. Field of the Invention
The present invention relates to wayside signaling and on-board locomotive acknowledgement systems for rail transportation and particularly to engineer and trainman acknowledgement systems.
2. Description of Related Art
A wide variety of wayside signal systems are known to the prior art. The system should require that both the trainman and engineer take positive steps to acknowledge a wayside signal between themselves provides additional assurance that the train operation will be in accordance with the signal. Existing communication systems are deficient in this regard in relying on only one operator being aware of the wayside signal and acting accordingly. In addition, significant portions of railroad are unsignalled (dark territory) and may have temporary speed restrictions, known as "slow orders", in effect from time to time. Existing systems do not make use of modern navigation methods such as GPS or onboard inertial navigation systems to implement and/or enforce slow orders. It is most desirable that speed restrictions both with regard to railcar type and track conditions require actual physical activity in the acknowledgement process with appropriate action (such as automatic stopping of the train) in the event that proper responses are not forthcoming. Improvements are therefore needed to provide for greater safety and train control.